1. Field of the invention
The present invention relates to an armrest for use on a vehicle seat and a method for forming the same. In particular, the invention is directed to a foamed armrest having a foam padding in its trim cover assembly, and also directed to a method for forming such kind of armrest under the steps of injecting and curing a liquid foaming blase material in a three-dimensional trim cover assembly preformed by sewing in a predetermined shape of armrest.
2. Description of Prior Art
In general, an armrest for use with a vehicle seat is mounted on a support shaft projected outwardly from a lateral side of seat back and rotatable about the shaft in a vertical direction. The armrest, therefore, may be selectively located in one of a horizontal use position and an upright non-use position, so that a passenger can rest his or her arm thereon at the horizontal use position, or can move the armrest to the upright non-use position set along the vertical line of seat back.
The ordinary formation of this kind of armrest is by sewing together plural trim cover materials into a predetermined cubic body of trim cover assembly, followed by injecting and curing a liquid foaming material in that cubic trim cover assembly to create a foam padding integrally therein. This process normally uses an injection nozzle to inject the liquid foaming material into the inside of the trim cover assembly. Namely, the injection nozzle is inserted in a given injection hole formed in the trim cover assembly and then the liquid foaming material is forced through the nozzle thereinto, after which, the liquid foaming material is cured to fill a mass of foam padding within the trim cover assembly.
Hitherto, the armrests thus formed have encountered such problem that an objectionable residual cured spot of the liquid foaming material remains at and around the injection hole in the trim cover assembly since a part of the liquid foaming material has been leaked outwardly through that hole during the foaming process and cured there into such objectionable spot. Because, as stated above, the armrest itself is rotated vertically, all walls of its body are to be exposed outwardly. This allows the objectionable cured spot to be viewed from the outside, impairing the outer aesthetic appearance of armrest, and also causes an unpleasant touch to a user whose arm contacts the wall part of armrest where the cured spot in question lies.
Moreover, at the step of injecting a liquid foaming material into the armrest trim cover assembly, it has been a common practice for a worker to use an injection nozzle fixed on a working table, while placing the trim cover assembly on the same table, and manually have the nozzle inserted into the injection hole of trim cover assembly. Such conventional steps have posed a difficulty in retaining an optimum position of the injection nozzle relative to the injection hole of trim cover assembly and caused the trouble that the liquid foaming material is not evenly filled in the trim over assembly, thus resulting in an incomplete creation of foam padding therein.
In view of the above-stated drawbacks, it is therefore a primary purpose of the present invention to provide an improved armrest for vehicle seat which not only insures a good cushiony touch on its all exposed walls, but also keeps an aesthetic appearance of the armrest.
To achieve such purpose, an armrest in accordance with the present invention is basically comprised of:
a connecting means provided between the armrest and a seat back, by way of which connecting means, the armrest is rotatably connected to the seat back;
an armrest body having a region so configured as to surround a part of the connecting means;
wherein the armrest body consists essentially of: a three-dimensional trim cover assembly having a local side defined on and along such region of the armrest body; a framework; and a foam padding, wherein the foam padding is filled in the trim cover assembly integrally together with the framework; and
an injection hole formed in the aforesaid local side of the trim cover assembly, which injection hole is adapted to allow an injection nozzle to be inserted therethrough into an inside of the trim cover assembly during a foaming process, so that a liquid foaming material is injected thereinto via the injection nozzle to create the foam padding.
In one aspect of the invention, the foregoing connecting means includes a tubular bearing disposed in the foregoing region of armrest body, in which tubular bearing, a support rod means is rotatably received for allowing the armrest body to be rotatable in a vertical direction, and the injection hole may be formed at any point in the local side of trim cover assembly such as to be in a coaxial alignment with the tubular bearing, so that, during the foaming process, the injection nozzle may be introduced through the tubular bearing into the injection hole, prior to mounting the support rod means rotatably in the tubular bearing.
Accordingly, the injection hole can be formed in such region of the three-dimensional trim cover assembly where the hole itself is invisible from the outside and kept away from contact with a user. Thus, any objectionable cured spot at the injection hole is concealed, which originates from a part of liquid foaming material that has been leaked through the hole and cured there during the foaming process. This effectively keeps aesthetic, the outer appearance of armrest, and insures to avoid any unpleasant hard touch of the spot to a user""s arm and other body portion.
It is a second purpose of the present invention to provide a method for forming the above-described armrest.
For that purpose, in accordance with the present invention, there is basically provided the steps of:
forming the injection hole at any point in the local side of cover assembly such as to set the injection hole in a coaxial alignment with the tubular bearing;
inserting the injection nozzle through the tubular bearing into the injection hole;
causing the liquid foaming material to flow through the injection nozzle and hole into an inside of the trim cover assembly;
then, curing the liquid foaming material into a foam padding filled in the trim cover assembly;
removing the injection nozzle from both tubular bearing and injection hole; and
inserting and rotatably securing the support shaft in the tubular bearing to thereby rotatably connect said armrest body to the seat back.
Accordingly, the tubular bearing is utilized as a guide through which the injection nozzle can be precisely introduced toward the injection hole. A worker can therefore conduct a stable positioning of the injection nozzle relative to the trim covert assembly, which assures to stabilize a flow of liquid foaming material via the nozzle and injection hole into the trim cover assembly, thereby creating a uniform resultant foam padding therein with its unchanged quality.
Another features and advantages of the present invention will become apparent from the description hereinafter, with reference to the annexed drawings.